mcs/class/referencesource/System.Data.Entity/System/Data/Common/QueryCache/EntitySqlQueryCacheKey.cs

   1 //------------------------------------------------------------------------------
   2 // <copyright file="EntitySqlQueryCacheKey.cs" company="Microsoft">
   3 //      Copyright (c) Microsoft Corporation.  All rights reserved.
   4 // </copyright>
   5 //
   6 // @owner  Microsoft
   7 // @backupOwner Microsoft
   8 //------------------------------------------------------------------------------
   9
  10 namespace System.Data.Common.QueryCache
  11 {
  12     using System;
  13     using System.Data.Objects;
  14     using System.Diagnostics;
  15
  16     /// <summary>
  17     /// Represents an Entity-SQL-based ObjectQuery Cache key context
  18     /// </summary>
  19     internal sealed class EntitySqlQueryCacheKey : QueryCacheKey
  20     {
  21         /// <summary>
  22         /// Aggregate hashcode based the hashcode of the properties of this cache key
  23         /// </summary>
  24         private readonly int _hashCode;
  25
  26         /// <summary>
  27         /// The name of the default container in effect when the Entity-SQL text was parsed
  28         /// (affects whether or not the text can be successfully parsed)
  29         /// </summary>
  30         private string _defaultContainer;
  31
  32         /// <summary>
  33         /// Entity Sql statement
  34         /// </summary>
  35         private readonly string _eSqlStatement;
  36
  37         /// <summary>
  38         /// Parameter collection token
  39         /// </summary>
  40         private readonly string _parametersToken;
  41
  42         /// <summary>
  43         /// Number of parameters
  44         /// </summary>
  45         private readonly int _parameterCount;
  46
  47         /// <summary>
  48         /// Concatenated representation of the Include span paths
  49         /// </summary>
  50         private readonly string _includePathsToken;
  51
  52         /// <summary>
  53         /// The merge option in effect
  54         /// </summary>
  55         private readonly MergeOption _mergeOption;
  56
  57         /// <summary>
  58         /// Result type affects assembly plan.
  59         /// </summary>
  60         private readonly Type _resultType;
  61
  62         /// <summary>
  63         /// Creates a new instance of ObjectQueryCacheKey given a entityCommand instance
  64         /// </summary>
  65         /// <param name="defaultContainerName">The default container name in effect when parsing the query (may be null)</param>
  66         /// <param name="eSqlStatement">The Entity-SQL text of the query</param>
  67         /// <param name="parameterCount">The number of parameters to the query</param>
  68         /// <param name="parametersToken">A string representation of the parameters to the query (may be null)</param>
  69         /// <param name="includePathsToken">A string representation of the Include span paths in effect (may be null)</param>
  70         /// <param name="mergeOption">The merge option in effect. Required for result assembly.</param>
  71         internal EntitySqlQueryCacheKey(string defaultContainerName,
  72                                      string eSqlStatement,
  73                                      int parameterCount,
  74                                      string parametersToken,
  75                                      string includePathsToken,
  76                                      MergeOption mergeOption,
  77                                      Type resultType)
  78             : base()
  79         {
  80             Debug.Assert(null != eSqlStatement, "eSqlStatement must not be null");
  81
  82             _defaultContainer = defaultContainerName;
  83             _eSqlStatement = eSqlStatement;
  84             _parameterCount = parameterCount;
  85             _parametersToken = parametersToken;
  86             _includePathsToken = includePathsToken;
  87             _mergeOption = mergeOption;
  88             _resultType = resultType;
  89
  90             int combinedHash = _eSqlStatement.GetHashCode() ^
  91                                _mergeOption.GetHashCode();
  92
  93             if (_parametersToken != null)
  94             {
  95                 combinedHash ^= _parametersToken.GetHashCode();
  96             }
  97
  98             if (_includePathsToken != null)
  99             {
 100                 combinedHash ^= _includePathsToken.GetHashCode();
 101             }
 102
 103             if (_defaultContainer != null)
 104             {
 105                 combinedHash ^= _defaultContainer.GetHashCode();
 106             }
 107
 108             _hashCode = combinedHash;
 109         }
 110
 111         /// <summary>
 112         /// Determines equality of two cache keys based on cache context values
 113         /// </summary>
 114         /// <param name="otherObject"></param>
 115         /// <returns></returns>
 116         public override bool Equals(object otherObject)
 117         {
 118             Debug.Assert(null != otherObject, "otherObject must not be null");
 119             if (typeof(EntitySqlQueryCacheKey) != otherObject.GetType())
 120             {
 121                 return false;
 122             }
 123
 124             EntitySqlQueryCacheKey otherObjectQueryCacheKey = (EntitySqlQueryCacheKey)otherObject;
 125
 126             // also use result type...
 127             return (_parameterCount == otherObjectQueryCacheKey._parameterCount) &&
 128                    (_mergeOption == otherObjectQueryCacheKey._mergeOption) &&
 129                     Equals(otherObjectQueryCacheKey._defaultContainer, _defaultContainer) &&
 130                     Equals(otherObjectQueryCacheKey._eSqlStatement, _eSqlStatement) &&
 131                     Equals(otherObjectQueryCacheKey._includePathsToken, _includePathsToken) &&
 132                     Equals(otherObjectQueryCacheKey._parametersToken, _parametersToken) &&
 133                     Equals(otherObjectQueryCacheKey._resultType, _resultType);
 134         }
 135
 136         /// <summary>
 137         /// Returns the hashcode for this cache key
 138         /// </summary>
 139         /// <returns></returns>
 140         public override int GetHashCode()
 141         {
 142             return _hashCode;
 143         }
 144
 145         /// <summary>
 146         /// Returns a string representation of the state of this cache key
 147         /// </summary>
 148         /// <returns>
 149         /// A string representation that includes query text, parameter information, include path information
 150         /// and merge option information about this cache key.
 151         /// </returns>
 152         public override string ToString()
 153         {
 154             return String.Join("|", new string[] { _defaultContainer, _eSqlStatement, _parametersToken, _includePathsToken, Enum.GetName(typeof(MergeOption), _mergeOption) });
 155         }
 156
 157     }
 158 }